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The Wall
Bob Harper

Bob Harper

Joined on December 20, 2004

Last Post on April 16, 2014

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good work vs. hackmasters

@ February 17, 2013 12:50 PM in garden hose for gas line

Some of the worst crimes I've seen were committed by "qualified licensed Pros" and passed the municipal inspections. Some of the best work I've seen has been by DIY'ers and unlicensed, "unqualified" pro- wannabe's that did not get a municipal inspection.

Codes and stds. are for the public safety and welfare, not just for one occupant but all those who enter that structure now and in the future. Codes do not guarantee performance but society has ruled (since Hammurabi) that we must do *something*. That something is not always what's best, effective or remotely 'safe', whatever that word means but it is a start. I've seen horrible piping jobs that should have blown up the house but didn't and I've investigated fires where there was beautiful workmanship with everything sized and laid out to code but something still failed causing damages.

CSST is a product that has been found to have certain potential defects and shortcomings. Some of these have supposedly been addressed by engineering, education and inspection. Time will tell. I have a list of other things like draft hoods I think are far more dangerous that should be banned because there is no way to make them reasonably safe from hazards under the conditions of use when operated by a reasonable and prudent person. Why do we still have draft hoods? Why don't draft hood equipped water heaters have ANY vent safety devices when a typical CAT I furnace has three yet they are allowed to be common vented, which defeats all three safeties on the furnace? Why do we install ionization "smoke alarms" that do not alert to the presence of smoke but only detect a free burning fire while we have photo sensors that do a very reliable job of sensing smoke, which btw is the most common form of unfriendly fires during the incipient stage? Why do we install alarms designed to protect against carbon monoxide death but do nothing to protect against carbon monoxide poisoning?

You and I have the knowledge to make a difference, Now, it is up to us to either apply that knowledge in the most effective manner and do the most good for the most people or else we, too become part of the problem.

legislative news

@ February 15, 2013 1:19 PM in legislative news

On Friday, February 8, 2013, the U.S. Court of Appeals for the D.C. Circuit issued its long-awaited decision in HPBA v. DOE.  The
decision addressed DOE’s April 16, 2010 and November 18, 2011 final
rules for “vented hearth heaters,” vacated DOE’s entire “vented hearth
heater” definition, and directed DOE to revise that definition
consistent with the court’s opinion. 

A more detailed legal analysis of the decision is attached and we will be holding a conference call on Wednesday, February 13th at 3:00 pm EST
(please note time change) to further discuss what the court’s decision
means, possible future developments, and provide time for a question and
answer session.

Key points of Friday’s decision include:

·         There are currently no DOE requirements scheduled to take effect on April 16, 2013 for any vented gas hearth products


o   The
court overturned DOE’s attempt to regulate decorative vented gas
fireplaces and vented gas log sets as “direct heating equipment”
(“DHE”), eliminating the “exclusion criteria” imposed by DOE;

o   The new  numerical values for annual fuel utilization efficiency (AFUE) still exist on paper, but do not currently apply to any products (heater-rated or decorative).


·         While the court case is a significant victory, DOE may seek to challenge the decision in one of the following ways:


o   An
appeals process, either to the entire panel of judges on the D.C.
Circuit, the same three judges who originally heard the case, or to the
U.S. Supreme Court;

o   A motion seeking clarification or modification of the court’s decision.


·         It is probable that DOE will attempt to use future rulemakings to regulate some vented hearth products going forward


o   DOE
is likely to attempt to define gas fireplace heaters as DHE, subjecting
these products to the AFUE standards in the 2011 Final Rule;

o   The
court’s decision and admonishment of DOE’s regulatory overreach make it
substantially harder for the court to regulate decorative vented gas
fireplaces or vented gas log sets without DOE going through a much
lengthier and more involved rulemaking process.

It will be interesting to see how this ruling affects other efforts by the DOE with regards to HVAC equipment. FYI, what happened here was the DOE from nowhere announced they were banning all vented gas logsets >9,000 BTU/hr input rating. The Hearth, Patio and BBQ Assn. had to sue in federal court for the right to sit at the table as the primary stakeholder in this ruling that would have essentially shut down an entire industry. After several years and hundreds of thousands of dollars this industry could not afford, we have this reprieve but as you can see it probably is not over. Meanwhile, the HPBA is also battling the EPA and local air quality districts over clean air/ emissions stds. and with the CPSC over them forcing mfrs. of glass covered direct vent gas fireplaces to make barrier screens that are cool to the touch because parents don't want to be responsible for supervising their children with a hot fireplace in the room. This can bankrupt the industry because they want us to go back, spend gobs of money in R&D testing and designing screens that are cool to the touch in front of a very hot fireplace then pay about $15K per size and model of every fireplace to be re-listed. You cannot simply add a screen because this would dramatically raise the heat signature of the fireplace and cause a fire hazard. They also are demanding each screen carry a label stating "Hot to touch". Not very aesthetically pleasing esp. for such a focal point of a room. Anyway, this is what's going on in a related industry and once they've done it here, it can be done to the HVAC, water heater, pool heater and other industries. Just like banning standing pilots over electronic ignition systems. I'll try to keep you updated as I get more info.

2lb for tankless and Fp

@ February 14, 2013 11:40 PM in 2LB system for Tankless Water Heater And Fireplace

You need to run the calculations. Do the Longest Run Method. At the very least, I would increase the pipe in from the meter to the tankless to 1" min. Since it is a short run, why not go bigger? You see, these things can draw so much gas so fast, they can drop out a standing pilot on fireplaces.

As for the piping shown, it is wrong. You can put a trap there but it is supposed to be close to the appliance. The biggest problem is the shutoff. It kills both appliances. You should relocate it to control the tankless only. You can put another shutoff on the leg to the fireplace right there in that room but you'll need one at the fireplace within 6 ft. under many codes. The IRC does allow the shutoff for a fireplace to be remote of the fireplace under three conditions: it controls only the Fp, it is labeled such and it is "readily accessible".

You are allowed to run 2 psi into the house then place a Medium Pressure regulator there, usually upstream of a manifold. You would need a shutoff then sediment trap, regulator, then another tee or means to tap for an outlet pressure. As stated, the inlet pressure to the appliances is on the rating plates but generally around 5-7 wci for NG and 10.5-11wci for LP with 14 wci/ 1/2psi max.


bathroom ventilation considerations

@ February 11, 2013 11:51 PM in Bathroom fan code?

Based upon the 2009 IRC:
min. 50 cfm intermittent ventilation or 20 cfm continuous
must discharge directly to outdoors--not attics, garages or crawlspaces
flex duct flame spread 200 or less
joints sealed with UL181 B-FX tape or 181 f-M mastic
three screws equidistantly spaced at connection to flanges
seal penetrations per energy code
fireblocking per R302.11
corrosion resistant screen, grilles, or louvers
outlet protected from direct weather
one wall switch controlled light-may be occupancy controlled


get a hearth pro

@ February 10, 2013 9:26 PM in propane tank gas fireplace regulator

I'm concerned about a number of things said here. First of all, a qualified professional should not be dissecting a precision gas control such as a regulator--if its bad, you replace it. There is too much unqualified monkeying around with this fireplace. For one, you never reduce the inlet pressure below mfr. specs.
There should be a rating plate attached to a metal tag to this appliance indicating the make, model, fuel setup, input BTU rating, listing and lighting instructions. No tag= unlisted logset, which should be removed from service and replaced with a listed set. There are two listings for vented gas logs: ANSI Z21.84 for basic set and Z21.60 for your std. vented gas logs. BTW, ventfree are listed to Z21.11.2b

All this is over the turndown rate?

misc techniques

@ February 9, 2013 4:56 PM in Eatherton "flux sponge"

Mark, I was expecting you to refer to using those cheap throw away foam paint brushes. I guess the main idea is to use the minimum flux that does the job and wipe off excess.

One thing I have not heard here was to scratch the thin face of the fitting cup so the solder bonds to it, too forming a cupped meniscus. I lay the abrasive cloth on a flat surface and lightly scrub the fitting face a few strokes. It makes for a nice curved fillet of solder. Pros vs. cons?

As ME said, reaming is required. This gets esp. important on smaller diameter tubes such as AC linesets because a little turbulence goes a long ways. Just remember about burrs: when you reduce a diameter by half, you reduce the flow by the CUBE function.

I work with home inspectors a lot and they find tons of corroded joints from the Flux Monster. I recommend a simply scrubbing with a Scotchbrite pad soaked with a mild bicarb bath. Be sure to wipe with a clean cloth because mixing the alkaline wash with the acid flux forms salts (acid + base > salt + water from your Jr. High School chemistry class). Don't trade one corrosive for another.

Lastly, do any of you use copper polish like used for kitchenware? I like to really shine up everything for the homeowner reveal and they love it. Again, rinse and wipe well.

duplicate thread

@ February 9, 2013 3:54 PM in gas garden hose

see thread on Main Wall

CO death from car exhaust shoveling snow

@ February 9, 2013 3:52 PM in CO death from car exhaust shoveling snow

Note the man was outdoors working and he went into respiratory arrest. People simply are not being given the facts or good advice regarding CO safety.

illegal gas piping?

@ February 9, 2013 10:17 AM in garden hose for gas line

I find illegal insane stuff all the time. Enclosed are pics of a twin home in Philly where the slum lord replaced a gas WH. Note the copper water flex line that uses hose threads and washers. The vent connectors on both boilers were disconnected. The vent connector on the other WH was so taped together you could barely see the Swiss cheese rusted out pipe. The unlined chimney fell over in a high wind leaving this venting into the attic. I called the gas utility to shut off the entire building.
I've seen them use PEX, electrical conduit, vacuum cleaner flex hose--you name it.

steel pipe connector thicknesses

@ February 9, 2013 12:36 AM in Duty of the HVAC technician according to law?

Per NFPA 211, 2010 ed., Table for oil, solid fuel-burning appliances, domestic-type incinerators, and gas appliances other than Cat. I appliances.


@ February 8, 2013 9:22 AM in Flame inside burner tube

As Timmie said, flashback is a function of too much primary air, too low manifold pressure or I would add high port loading or mechanical defects impeding the natural flow of mixed gas to the burner ports. Often, a subtle mis-alignment in the burners or how they are engaged with the burner orifice spud can do it. Gauge the burner orifice to ensure it is spec. Sometimes on LP, this can happen with the burner tilted uphill. Perform combustion analysis and look into each burner while firing. Try switching burner tubes to see if it is the tube or the position. Make sure there are no vent restrictions in the HX or common vent and you have proper draft--too high or too low are problems.  Lastly, when in doubt, measure the manifold pressure directly off the valve downstream before the burner where possible. You need to ascertain if this is due to an increase in flame speed vs. a mechanical defect.


backflow protection

@ February 7, 2013 8:10 PM in check valve

You will find that in the applicable plumbing code but it is also an EPA reg. that your local water board can and will enforce. Need isolation valves to test and service. As stated, double check with atmospheric vent. If you install a bypass around an automatic feed valve for fast refilling such as after equipment replacement, the bypass must also be backflow protected.

CDS1 interpretation?

@ February 7, 2013 8:05 PM in CSD-1 applicability question

As i read it, you must has a lockable d/c at the appliance plus the emergency d/c either immediately outside the CAZ or just inside the door if it opens to the outside. one d/c per door.

If the d/c kills the power OR the fuel, it is ok.

Yep, looks to be all safeties on the other side of the system only. That mean a trip would kill all the power to the unit.

2009 IRC Table E4101.2 lists the disconnecting means per the appliance application. >1/8HP motor requires lockout d/c within sight of the equipment.

The 2009 IRC references CSD-1 and the ASME Boiler and Pressure Vessel Code Sections I and IV. Anyone have a copy of this Code?

one small help from NFPA

@ February 2, 2013 5:41 PM in Duty of the HVAC technician according to law?

Here is an example of how NFPA tries to help a little bit. You can read their stds. online for free but they have done an excellent job of protecting them so you cannot print or save them. At least it gives you access to the current version online. Then you can decide if you need to purchase it or not. Good for the occasional peek.

One way to get the I-codes for residential is to join the ICC then choose the  IRC for your choice of one free code book. You can become a voting member and get a code book for $20 less than the code book alone. Note that many codes such as NFPA and ICC are now including notations on sections that changed from the previous edition. That gives you 6 yrs. of coverage: 3 fwd and 3 looking back. One valuable benefit of joining the NFPA and ICC is access for technical support and opinions. This has easily paid for the membership a number of times. Nothing like a letter from Ted Lemoff on a gas code issue to quiet the most arrogant AHJ.

biggest stumbling block

@ February 2, 2013 1:35 PM in Duty of the HVAC technician according to law?

Tim hit on what I think is the biggest stumbling block which is the aggregate cost of all the codes, stds. and regs we are held accountbable to by law. Most UL and ANSI stds. run btw $700-900 each. Most codes and stds .get revised every 3 yrs. Now, add to that the ASHRAE Handbooks, ACCA manuals, etc. and it really adds up. Want more fun? Throw in the National Roofing Contractors Assn. Manual set of 4 at $650 just in case you have to mess with roofing systems;

There was a lawsuit about 10 yrs ago where the Southern Bldg. Code Congress sued over someone publishing their entire code online for free. They prevailed over the SBCCCI because the court found the public and contractors must have "reasonable" access to the rules they are held to. Not sure why this hasn't spilled over to all the codes. I don't have a problem paying for printing cost plus a reasonable profit but most of these are out of touch for the average guy.

sidewall power venter

@ January 31, 2013 2:24 PM in Sidewall venting

Jim is essentially correct with one caveat: if a mfr. of an appliance specifically forbids sidewall power venting, then no. Otherwise, there is a "transfer of liability" or an "assumption of risk" on the part of the power vent mfr.. Regardless, a few rules: the power vent must incorporate a pressure switch that proves a pressure change signifying supposed sufficient air flow. This is not bulletproof but is considered an acceptable safety control. The powerventer must be interlocked. Basically, on a call for heat, it pre-purges, senses sufficient negative pressure, closes the contact to the furnace controls and allows the normal sequence of operation to continue. Should be vent become blocked, loss of power, or thermostat satisfied, the fan de-energizes, vent pressure equalizes causing the pressure switch to open causing the furnace to shut off. Now, some can incorporate a post purge cycle, which is desirable to mitigate condensation.

You still must maintain stated clearances to combustibles on vent pipe unless specifically tested as listed as a system. Same with vent sizing, unless engineered system accepted by the AHJ. Check local codes for vent termination restrictions over and above national codes and the product listing. The most restrictive requirements apply such as height above snow line.

Duty of the HVAC technician according to law?

@ January 28, 2013 6:34 PM in Duty of the HVAC technician according to law?

The HVAC technician is burdened with so many layers of laws, standards, regulations, and instructions it is bewildering. I figured I'd start a thread just to get some dialogue going:

In a State where you have building codes, those codes are the LAW. They are not suggestions or Best Practices. They are what you will be held to in a court of law should there be a loss with damages/ injuries. Now, a municipal building official is a Code Enforcer--not a Code Legislator (I'll wait for the laughter to subside). There is a legal mechanism to change local codes. Once the State has adopted a code, the local municipalities may or may not be allowed to accept it depending upon your State laws. For instance, the Statutes in Pa. allow municipalities to "opt out" of the Pa Uniform Building Code, which is essentially the 2009 ICC code suite. Therefore, when you work in each of the various 1,347 or so jurisdictions within the Commonwealth, you need to know if they adopted the Pa UBC/ IRC or kept the old BOCA codes. Regardless of what an inspector tells you, you are held to that code that was voted into law. He legally does not have the power to willy nilly change the code to suite his purposes. In order to change a local code (ordinance), you must submit the request to the governing body with substantial documentation on why this change is relevant and necessary, what the drawbacks are, economic burden, inspection and enforcement ramifications, etc. Once the Council has voted to proceed, you need three public hearings so stakeholders and the public can comment. If adopted, then and only then does it become an enforceable law.

Now, within that code are references to various other codes, standards, regulations, etc. By Statute, you are held to those standards the same and the full body of the code. For example: You go to replace an oil fired boiler with a gas fired one. Do you have any obligation to inspect or reline the chimney and if so by what authority? The IRC says for gas appliances, refer to NFPA 211 for what constitutes an acceptable masonry chimney. Now, the IRC details in Ch 10 how to build a masonry chimney and fireplace and that is not as restrictive as 211. So, which do you refer to? 211. It is specified in G2427.5.2 specifically. Moreover, it is also almost universally referred to in all installation manuals. So, what does 211 say? Well, that's a whole week long inspection cert. course but suffice it to say no existing masonry heater flue can pass a Level II inspection per Ch14 of NFPA 211 without a listed liner. So, you will have to reline.

 What about  an oil fired boiler installation? Well, the IRC refers you to NFPA 211 for the chimney, NFPA 31 for the general oil burner requirements and ASME CSD-1 for the boiler installation.

What about using listed factory built chimney or venting? The IRC simply states to refer to the listed instructions of that vent mfr. What if the listing calls for a clearances less than that typically stated in the code? Those clearances in the code are intended for unlisted appliances or when the listed instructions cannot be located. However, if a mfr. has tested and listed their product at a reduced clearance, then you may go with the listed spec.. Listings trump codes. Codes are general rules for the absence of engineered, tested, listed appliances and products.

That ought to stir some discussion. Enjoy!

chimney cap resistance and ice

@ January 27, 2013 12:15 AM in ModCon Icing on Chimney

That ss chimney cap is not an approved termination for any condensing gas appliance I'm aware of. Technically, it could be treated as a "shroud", which would require it to be listed with that appliance. This is a ForeverCap, which has a high static pressure compared to most other designs. NFPA 211 calls for a net free area 4x the area of the flue but that is for "chimneys". This std. does not consider placing a chimney cap over a condensing gas furnace flue gas outlet. Functionally, one can see where the ice is partially blocking the mesh on this cap further increasing the static pressure or making it harder to exhaust out of it. This cap is made of 304 stainless steel and will rot out from the acidic flue gases. Since PVC is not listed in the US (in Canada they have the S636 std.) there is no listed termination. Therefore, the code refers you to the listed instructions of the appliance. This plastic pipe would need a flashing so a water tight seal is made to keep water out of the flue. Much of the condensate that is not freezing is a dilute solution of carbonic and other acids. Acids generally do not freeze until supercooled. The do eat up the alkaline masonry. The acid can draw water from the interior of the brick to the face where the osmotic pressure can spall brick. Over time, the acid can eat away the hard fired face of the brick thus making it more porous and making it prone to freeze-thaw damage. 

what's inside the flue?

@ January 24, 2013 9:12 PM in ModCon Icing on Chimney

What is this mod-con venting into? Is there pvc, stainless steel liner or just flue tile? 

chimney inspection

@ January 21, 2013 1:02 PM in steam boiler conversion from Oil to Natural Gas?

You will need an NFPA 211- Level II chimney inspection to ensure the suitability of this chimney for this use. If not properly lined or deteriorated, it will require a properly sized and type chimney liner. 

other issues

@ January 21, 2013 12:55 PM in Should the low water cut-off be installed horizontally?

That foil tape needs to come off the vent connector. Even though it carries a UL 181 listing, it is approved for warm air ducts and not vent/ chimney connectors. More specifically, it is prohibited by NFPA 211 because it conceals the condition of the pipe. If you think you need to seal the crimped joints, use furnace cement but since this is negative pressure venting, this should be unnecessary.

If the boiler mfr. does not specify a minimum water level then you can place the LWCO anywhere above the boiler you like. This is a little higher than typically found but doesn't hurt.
When you drop the water in the boiler to replace the pressure relief valve every 3 yrs you can remove the LWCO and service the probe unless the mfr. requires a more frequent schedule.


@ January 16, 2013 2:15 PM in Water heater causes nearby spray can to explode?

Location, location, location. If the can was close up to raise the surface temp. on the can above 120F then yes it could have led to a rupture of the can. The question is, what part of a properly installed and operating WH gets that hot? Well, for one, on a gas WH, a single walled vent connector has a 6" clearance to combustibles. If there was a chimney blockage or other venting failure then yes, sufficient heat may have spilled out in an abnormal way. Regardless, it should be inspected by a professional. 
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